Re: Did Commodore cheat with the quad density floppies?

Den Wed, 15 May 2019 14:35:06 +0100 skrev smf <smf_at_null.net>:
> On 13/05/2019 20:51, Ethan Dicks wrote:
> 
> > The benefits of the PS/2 was on the IBM side, to attempt to
> > recapture the desktop from the Taiwanese clone makers.
> 
> I disagree. VGA was a benefit to everyone, so was the 16550 UART and
> 1.44mb 3.5" floppy. The mouse and keyboard port is arguable, but to me
> the smaller connector and the simplified mouse hardware support was a
> benefit (you didn't have to waste your only serial port or an ISA slot
> just for the mouse).

Agree that VGA were a great improvement.

The UART would had happened eventually anyways.

Btw the industry did adopt the 1.44M 3.5" floppy, but more or less
every other manufacturer let the disks tell the computer if they are HD
or DD, while IBM PS/2 required you to spec that on the command line
when formatting the disk. The default on a PS/2 when using a DD disk
was to incorrectly format it as a HD disk and then to be able to read
it on another computer you had to punch a hole for the density sensor.
Brain dead designe deluxe++

> All of those things were incorporated by the PC clones, so they must
> have considered them a benefit too.

It took ages for the PS/2 connectors to be standard on no-name PC's
though. ATX were the first general standard that used them, although
some manufacturers did agree on some earlier standards like ETX who IBM
and Compaq used.

> The MCA based machines we used were made by NCR and the SCSI
> controller, multiport serial port controllers and network cards were
> touted as being second to none. We used PC clones for machines that
> didn't need that complexity of hardware.

The SCSI controllers performance were probably better over MCA than
over ISA, but a multi serial port could technically be just as good on
ISA as on MCA.

> I own a ford, but I don't claim that Lambourghini are terrible for
> making cars that are more expensive.

You could however argue that Citroen makes cars that's only suitable to
enthusiasts and people who lack any kind of technical skills (i.e.
usually a language teacher ;) ) :) :)

> > But that was the entire point of the MCA bus - a proprietary bus
> > (that did happen to include some technical fixes to real
> > limitations of the ISA bus) to promote corporate sales of genuine
> > IBM machines.  The last thing IBM wanted was a bus anyone could
> > make cards for.
> 
> Sure IBM wanted their share of the money, isn't that what everyone
> invents new products?
> 
> The industry instead went with E-ISA. Which is a standard war just
> like Beta max vs VHS or HD-DVD vs Bluray.

No, rather like the format war with 4-channel vinyl records, where CD-4
would compare to MCA and all the others (SQ, QS and whatever they were
called) would compare to EISA. If you played a CD-4 record on a regular
2-channel stereo the pickup/needle would damage the record and you'd
hear a 15kHz pilot tone damaging your ears and speakers, while the
others could be played without problems. Trying to fit an ISA card in a
MCA slot would cause havoc, while ISA cards did fit in EISA slots.

> > but really, the coming of Windows 3.x created the demand
> > for _some_ graphic bus, and outside of IBM, that followed the
> > VLB->PCI progression.
> 
> At least some of the PS/2 had on board video, they weren't
> particularly looking at graphics busses.

Were there any PS/2 that didn't have some graphics on board?

> IBM PC was 1981, XT was 1983, AT was 1984, PS/2 was 1987, EISA was
> 1988.
> 
> That was how quickly technology was changing, I'm not convinced there
> was a huge demand in 1992 for VLB & PCI. Intel chipsets started
> supporting it, other manufacturers followed and then most customers
> got used to them. There wasn't really a PC games industry that was
> pushing for ever faster hardware at the time. There wasn't really any
> OS support for PCI until Windows 95.

Side track: The industry did even try to workaround the lack of OS
support for PCI. Afaik the HP Vectra XU 5-90, a dual CPU Pentium-1
computer with PCI bus from iirc 1994, did report the PCI cards as if
they were EISA cards. That probably made sense at the time but causes
trouble when trying to run Linux on it.

> IBM miscalculated their importance as technical leaders of the market,
> but only because up until that point everyone had followed them.

One thing worth remembering was that in the beginning only small/new
companies dared making PC compatibles (Compaq and Columbia). The IBM AT
was mostly rather obvious, the only thing that IBM did that might not
had been obvious to anyone trying to combine a 286 processor with the
PC/XT design were the A20 gate and the exact pinout of the 16-pin
extension of the ISA bus. There were no technical reasons for not
following what IBM did if you were to make a 286 computer.

> It was only when IBM asked the clone manufacturers to help foot the bill
> of the R&D if they were going to steal their lunch that it broke
> down.

I'm not so sure that MCA had been a success even if it had been free to
copy.

The fact that you had to fiddle with various setup diskettes and stuff
to even get the computer to run MS-DOS with a new card installed
probably led people to think that MCA was just as much hassle as ISA
was.

> Apple also tried to get people to pay to play manufacturing Mac
> clones and decided to stick with a monopoly when that didn't work.


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